Optimal placement of distributed generations considering voltage stability and power losses with observing voltage-related constraints

Distributed Generations (DGs) can be an efficient solution to today's power system environmental and economical challenges. Installing DGs influences power system stability and losses. In this paper, a method is presented for locating and sizing of DGs to enhance voltage stability and to reduce network losses simultaneously. First, vulnerable buses from voltage stability point of view are determined using bifurcation analysis as the best locations to install DGs. Number of DGs is so chosen that system voltage profile is brought into the given permissible voltage security limits. Then, the global optimal size of DGs is determined employing the dynamic programming search method. It is shown that considering DG reactive limits makes different voltage stability bifurcations happen and it affects the optimal location, size, and number of DGs. Results of testing the proposed method and previous methods on a 34-bus distribution test system are discussed in detail and they show the efficiency of the proposed method. (C) 2013 Elsevier Ltd. All rights reserved.